Sunday, January 19, 2014

EV Simulator backpack

I've been selling the EV Sim Mark II for a few months now, and since I've been making a lot of "backpack" projects lately, and because so far as I know most folks who buy an EV Sim II hook it straight up to an RGB LCD backpack, I've decided to try and simplify the hardware for the most frequent use case, so I've come up with an ATTiny84 backpack.

I've built and tested the prototype, and it works perfectly. It's for sale in the store now.

R2 depends on your LCD. For the LCDs I've been sourcing from DigiKey, the correct value is actually zero ohms, but rather than omit the resistor entirely I have a pile of "0 ohm" 0805 resistors I use. That way the board design is more flexible.